You might have expected "the largest gathering of witches in the world" to meet somewhere spooky, like Salem, Transylvania, or even Whitby. But no, this annual celebration of the otherworldly and occultish takes place in – wait for it! – Croydon. Modern-day Morgan Le Fays can enjoy talks by Wiccan history expert Ron Hutton and Most Haunted's David Wells, plus there'll be workshops in wand-making, "astro dating" and even morris dancing. Pick up a potion at the "esoteric market" and shake your pentagrams to music from goth favourites Inkubus Sukkubus (pictured). Thankfully, England's last witch execution was way back in 1684, so there's no risk of being burned at Croydon power station.

Bringing a mischievously artistic edge to the idea of the flashmob, this participatory sound and performance piece from Duncan Speakman invites couples to congregate at secret locations in London, Bristol and Liverpool on consecutive evenings, where they will be immersed in a filmic altered reality. With headphones donned, the crowd will work at the behest of an MP3 file and the voices that come to them, which will be subtly different for various groups within the larger mass. Working with Sadie Anderson of Chrome Hoof, Speakman has created what should make for a disorienting night's entertainment for those who are game enough to sign up online and take part.

Subtitled Art In An Ephemeral Age, but far from a throwaway programme, taking in art, music, spoken word and heavyweight panel discussions. It all kicks off with The Paper Cinema, a beautiful, magical and surreal blend of film and hand-drawn puppets. The debate strand takes in artist Richard Wentworth and historian Marcus Quint, but look out for a live outing from oddball art-punk hero Richard Strange (pictured), whose latterday acting career has seen him veer wildly between working with Martins Scorsese and Clunes.